Cecil County Department of Public Works Stormwater Management Ordinance Chapter 251 of the Cecil County Code

Refer to the SWM Guidance Manual

To view the Cecil County Stormwater Management Ordinance in .pdf format, click here.

[Note: This unofficial excerpt of the Cecil County Code is made available in this form for the convenience of interested parties and only the official Cecil County Code should be relied upon.]

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Adopted By The Board Of County Commissioners Of Cecil County February 19, 2002

ARTICLE I

251-1 PURPOSE AND AUTHORITY

The purpose of this Ordinance is to protect, maintain and enhance the public health, safety, and general welfare by establishing minimum requirements and procedures to control the adverse impacts associated with increased stormwater runoff. Proper management of stormwater runoff will minimize damage to public and private property, reduce the effects of development on land, control stream channel erosion, reduce local flooding, and maintain after development, as nearly as possible, the pre-development runoff characteristics. The provisions of this Ordinance, pursuant to the Environment Article, Title 4, Subtitle 2, Annotated Code of Maryland, 1987 replacement volume, are adopted under the authority of the Cecil County Code and shall apply to all development occurring within the unincorporated area of Cecil County. The application of this Ordinance and provisions expressed herein shall be the minimum stormwater management requirements and shall not be deemed a limitation or repeal of any other powers granted by State of Maryland statute. The Cecil County Department of Public Works shall be responsible for the coordination and enforcement of the provisions of this Ordinance. All previous stormwater management ordinances and/or policies relating thereto, are hereby repealed and replaced with this Ordinance.

251-2 INCORPORATION BY REFERENCE

For the purpose of this Ordinance, the following documents are incorporated by reference:

A. The 2000 Maryland Stormwater Design Manual, Volumes I & II, (Maryland Department of the Environment, April 2000) is incorporated by reference by the Cecil County Department of Public Works and shall serve as the official guide for stormwater principles, methods, and practices.

B. USDA Natural Resources Conservation Service Maryland Conservation Practice Standard Pond Code 378 (January 2000).

ARTICLE II

251-3 DEFINITIONS

A. For the purpose of this Ordinance, the following definitions describe the meaning of the terms used in this Ordinance:

(1) "Administration" means the Maryland Department of the Environment (MDE) Water Management Administration (WMA).

(2) "Adverse impact" means any deleterious effect on waters or wetlands, including their quality, quantity, surface area, species composition, aesthetics or usefulness for human or natural uses which are or may potentially be harmful or injurious to human health, welfare, safety or property, to biological productivity, diversity, or stability or which unreasonably interfere with the enjoyment of life or property, including outdoor recreation.

(3) "Agricultural land management practices" means those methods and procedures used in the cultivation of land in order to further crop and livestock production and conservation of related soil and water resources.

(4) "Applicant" means any person, firm, or governmental agency that executes the necessary forms to procure official approval of a project or a permit to carry out construction of a project.

(5) "Aquifer" means a porous water bearing geologic formation generally restricted to materials capable of yielding an appreciable supply of water.

(6) "Best Management Practice (BMP)" means a structural device or nonstructural practice designed to temporarily store and/or treat stormwater runoff in order to mitigate flooding, reduce pollution, and provide other amenities.

(7) "Channel Protection Storage Volume (CPV)" means the volume used to design structural management practices to control stream channel erosion. Methods for calculating the channel protection storage volume are specified in the 2000 Maryland Stormwater Design Manual, Volumes I & II.

(8) "Clearing" means the removal of trees and brush from the land but shall not include the ordinary mowing of grass, or the removal of dead trees and noxious weeds.

(9) "Coastal Plain Region" means those areas south of the Chesapeake and Delaware Canal, not including the Elk Neck Peninsula.

(10) "Department of Public Works" means the Cecil County Department of PublicWorks.

(11) "Design Manual" means the 2000 Maryland Stormwater Design Manual, Volumes I & II that serves as the official guide for stormwater management principles, methods, and practices.

(12) "Detention structure" means a permanent structure for the temporary storage of runoff, which is designed so as not to create a permanent pool of water.

(13) "Developer" means the property owner or other party who plans or executes the development of land.

(14) "Develop land" means to change the runoff characteristics of a parcel of land in conjunction with residential, commercial, industrial, or institutional construction or alteration.

(15) "Direct discharge" means the concentrated release of stormwater to tidal waters or vegetated tidal wetlands from new development or redevelopment projects in the Critical Area.

(16) "Disturb" means the grading, moving, or digging of soils, the removal of grass and other ground covers, placement of fill or surface material (such as stone, concrete, asphalt), or the removal of stumps.

(17) "Drainage area" means that area contributing runoff to a single point measured in a horizontal plane, which is enclosed by a ridgeline.

(18) "Easement" means a grant or reservation by the owner of land for the use of such land by others for a specific purpose or purposes, and which must be included in the conveyance of land affected by such easement.

(19) "Exemption" means those land development activities that are not subject to the stormwater management requirements contained in this Ordinance.

(20) "Extended detention" means a stormwater design feature that provides gradual release of a volume of water in order to increase settling of pollutants and protect downstream channels from frequent storm events. Methods for designing extended detention BMPs are specified in the Design Manual.

(21) "Extreme flood volume (QF)" means the storage volume required to control those infrequent but large storm events in which overbank flows reach or exceed the boundaries of the 100 - year floodplain.

(22) "Flow attenuation" means prolonging the flow time of runoff to reduce the peak discharge.

(23) "Grading" means any act by which soil is cleared, stripped, stockpiled, excavated, scarified, filled or any combination thereof.

(24) "Infiltration" means the passage or movement of water into the soil surface.

(25) "Off-site stormwater management" means the design and construction of a facility necessary to control stormwater from more than one development.

(26) "On-site stormwater management" means the design and construction of systems necessary to control stormwater within an immediate development.

(27) "Overbank flood protection volume (QP)" means the volume controlled by structural practices to prevent an increase in the frequency of out of bank flooding generated by development. Methods for calculating the overbank flood protection volume are specified in the Design Manual.

(28) "Piedmont Region" means those areas north of Interstate I-95.

(29) "Recharge volume (ReV)" means that portion of the water quality volume used to maintain groundwater recharge rates at development sites. Methods for calculating the recharge volume are specified in the Design Manual.

(30) "Redevelopment" means any construction, alteration, or improvement exceeding 5000 square feet of land disturbance performed on sites where existing land use is commercial, industrial, institutional or multifamily residential.

(31) "Retention structure" means a permanent structure that provides for the storage of runoff by means of a permanent pool of water.

(32) "Retrofitting" means the construction of a structural BMP in a previously developed area, the modification of an existing structural BMP, or the implementation of anonstructural practice to improve water quality over current conditions.

(33) "Sediment" means soils or other surficial materials transported or deposited by the action of wind, water, ice, or gravity as a product of erosion.

(34) "Site" means:

(a) for "new development" any tract, lot, or parcel of land or combination of tracts, lots, or parcels of land, which are in one ownership, or are contiguous and in diverse ownership where development is to be performed as part of a unit, subdivision, or project.

(b) for "redevelopment" the area of new construction as shown on an approved site plan; or the original parcel. Final determination of the applicable area shall be made by the Department of Public Works.

(35) "Stabilization" means the prevention of soil movement by any of various vegetative and/or structural means.

(36) "Stormwater management" means:

(a) For quantitative control, a system of vegetative and structural measures that control the increased volume and rate of surface runoff caused by man-made changes to the land; and

(b) For qualitative control, a system of vegetative, structural, and other measures that reduce or eliminate pollutants that might otherwise be carried by surface runoff.

(37) "Stormwater Management Plan" means a set of drawings or other documents submitted by a person as a prerequisite to obtaining a stormwater management approval, which contain all of the information and specifications pertaining to stormwater management for the site.

(38) "Stripping" means any activity that removes the vegetative surface cover including tree removal, clearing, grubbing and storage or removal of topsoil.

(39) "Transition Region" means those areas north of the Chesapeake & Delaware Canal and South of Interstate I-95 including the Elk Neck Peninsula.

(40) "Variance" means the modification of the minimum stormwater management requirements for specific circumstances such that strict adherence to the requirements would result in unnecessary hardship and not fulfill the intent of the Ordinance.

(41) "Waiver" means the relinquishment from stormwater management requirements by the Cecil County Department of Public Works for a specific development on a case-by-case review basis.

(a) "Qualitative stormwater management waiver" includes water quality volume and recharge volume design parameters.

(b) "Quantitative stormwater management waiver" includes channel protection storage volume, overbank flood protection volume, and extreme flood volume design parameters.

(42) "Watercourse" means any natural or artificial stream, river, creek, ditch, channel, canal, conduit, culvert, drain, waterway, gully, ravine or wash, in and including any adjacent area that is subject to inundation from overflow or flood water.

(43) "Watershed" means the total drainage area contributing runoff to a single point.

(44) "Water quality volume (WQv)" means the volume needed to capture and treat the runoff from 90 percent of the average annual rainfall volume at a development site. Methods for calculating the water quality volume are specified in the Design Manual.

ARTICLE III - APPLICABILITY

251-4 Scope

No person shall develop any land for residential, commercial, industrial, or institutional uses without having provided stormwater management measures that control or manage runoff from such developments, except as provided within this section. The stormwater management measures must be designed consistent with the Design Manual and constructed according to an approved plan for new development or the policies stated in section 251-7 for redevelopment. In establishing compliance with this Ordinance, the addition of impervious surfaces or other changes in site conditions (land cover types, slopes, etc.) shall be considered cumulative from August 28, 1984 (Date of Adoption of original Cecil County Stormwater Management Ordinance).

251-5 Exemptions

The following development activities are exempt from the provisions of this Ordinance and the requirements of providing stormwater management:

A. Agricultural land management practices;

B. Additions or modifications to existing single family detached residential structures if they comply with Subsection C below;

C. Developments that do not disturb more than 5,000 square feet of land area;

D. Land development activities that the Administration determines will be regulated under specific State of Maryland laws, which provide for managing stormwater runoff.

251-6 Waivers/Watershed Management Plans

A. The Department of Public Works may grant a stormwater management quantitative control waiver under the following circumstances:

(1) Projects developed in accordance with a watershed management plan consistent with Section 251-6C of this Ordinance.

(2) Developments that have direct discharge(s) to tidally influenced receiving waters.

(3) When the Department of Public Works determines that circumstances exist that prevent the reasonable implementation of quantity control practices.

(4) Developments located in the Coastal Plain Region that do not generate more than a ten (10) percent increase of the two year pre-development peak discharge rate and that will not cause an adverse impact on the receiving wetland, watercourse or waterbody.

B. The Department of Public Works may grant a stormwater management qualitative control waiver under the following circumstance:

(1) Redevelopment projects consistent with Section 251.7 of this Ordinance.

C. The Department of Public Works may permit different stormwater management quantitative control measures then those specified in Section 251-9 of this Ordinance if the quantitative control measures are consistent with a Watershed Management Plan. Watershed Management Plans may be prepared by a public or private entity and shall:

(1) Include detailed hydrologic and hydraulic analyses to determine hydrograph timing;

(2) Evaluate both quantity and quality management;

(3) Include cumulative impact assessment of watershed development;

(4) Identify existing flooding and receiving stream channel conditions;

(5) Be conducted at a reasonable scale;

(6) Specify where on-site or off-site quantitative and qualitative stormwater management practices are to be implemented;

(7) Be consistent with the General Performance Standards for Stormwater Management in Maryland found in Section 1.2 of the Design Manual; and

(8) Be approved by the Administration.

D. Watershed Management Plans that propose different stormwater management requirements than those specified in Section 251-9 of this Ordinance shall be adopted by the Board of County Commissioners of Cecil County and shall be incorporated into this Ordinance by reference.

E. The Department of Public Works may grant a waiver of requirements for individual developments under the above conditions provided that a written request is submitted by the applicant containing descriptions, drawings, and any other information that is necessary to evaluate the proposed development. A separate written waiver request shall be required in accordance with the provisions of this section if there are subsequent additions, extensions, or modifications to a development receiving a waiver. In addition to the above criteria, the Department of Public Works may also consider potential adverse impacts of the proposed development to adjacent or downstream properties.

251-7 Redevelopment

A. The recharge volume, channel protection storage volume, and overbank flood protection volume requirements specified in the Design Manual do not apply to redevelopment projects unless specified by the Department of Public Works.

B. All redevelopment projects shall reduce existing site impervious areas by at least 20 percent. Where site conditions prevent the reduction of impervious area, then stormwater management practices shall be implemented to provide qualitative control for at least 20 percent of the site's impervious area. When a combination of impervious area reduction and stormwater practice implementation is used, the combined impervious area reduced or stormwater treated shall equal or exceed 20 percent of that pre-existing at the site.

C. Where conditions prevent impervious area reduction or on-site stormwater management, practical alternatives may be considered, including but not limited to:

(1) Off-site BMP implementation for a drainage area comparable in size and percent imperviousness to that of the project;

(2) Watershed or stream restoration; or

(3) Retrofitting.

251-8 Variances

The Department of Public Works may grant a written variance from any requirement of Section 251-9 of this Ordinance if there are exceptional circumstances applicable to the site such that strict adherence will result in unnecessary hardship and not fulfill the intent of the Ordinance. A written request for variance shall be provided to the Department of Public Works and shall state the specific variances sought and reasons for their granting. A variance shall only be granted if the Department of Public Works determines that sufficient justification has been provided by the applicant developing the site.

ARTICLE IV - STORMWATER MANAGEMENT CRITERIA

251-9 Minimum Control Requirements

A. The minimum control requirements established in this section and the Design Manual are as follows:

(1) In the Coastal Plain Region, the following minimum control requirements apply in accordance with the Design Manual:

(a) Water Quality Volume

(b) Recharge Volume

(c) Overbank Flood Protection Volume for the 2-year frequency storm event

(2) In the Piedmont Region, the following minimum control requirements apply in accordance with the Design Manual:

(a) Water Quality Volume

(b) Recharge Volume

(c) Channel Protection Storage Volume

(3) Except as provided below, in the Transition Region the minimum control requirements shall be those as specified for the Piedmont Region. If an applicant demonstrates that the site to be developed within the Transition Region contains predominantly Coastal Plain characteristics for topography and soils, then the minimum control requirements and applicable waiver provision as specified for the Coastal Plain shall apply. To be considered predominantly Coastal Plain topography the average slope on the site to be developed, from the highest elevation to the lowest elevation, must be eight (8) percent or lower. To be considered predominantly Coastal Plain soils, the site to be developed must contain greater than fifty (50) percent of soils classified in the following Soil Associations:

(a) Keyport - Loamy & Clayey land - Beltsville Association

(b) Sassafras - Woodstown Association

(c) Matapeake - Butlertown Association

(d) Collingtown - Sassafras - Aura Association

(e) Mattapex - Elsinboro - Othello Association

(4) In addition to the applicable requirements above, all development and redevelopment activities that take place in the Intensely Developed Areas (IDA) of the Cecil County Critical Area shall result in a reduction of pollutant loadings from the site by at least ten (10) percent. The process for determination of pollutant loading reduction shall be as outlined by the Critical Areas Commission in "A Framework for Evaluation of Compliance With The 10% Rule in the Critical Area", April 1987 or a comparable methodology as approved by the Department of Public Works.

(5) In all areas of the County, applicants for developments not eligible for a quantitative stormwater management waiver, shall perform an analysis of downstream stormwater facilities to determine if those facilities can accommodate the post-development peak discharge from the 24-hour ten-year storm event. In order for a facility to be deemed capable of accommodating the flow there must be no adverse impact on adjacent property by the impeding drainage or by an increase in the water surface elevation on the properties adjacent to the stormwater facility. The extent of analysis shall include all downstream stormwater facilities, including swales, storm drainage pipes, culverts and other points of constriction, to a point or points in the drainage area where the post-development peak discharge from the 24-hour ten-year storm on the site to be developed, is less than ten percent of the total flow from the 24-hour ten-year storm on the entire area contributing to that point or points. If a stormwater facility cannot accommodate the flow, then the Overbank Flood Protection Volume for the peak discharge from the 24-hour ten-year storm event must be provided in addition to any other applicable minimum control requirement as specified in this Ordinance. In lieu of proving this control, the applicant may replace the impacted stormwater facility. This downstream analysis shall include descriptions, drawings, and any other information as required by the Department of Public Works. In lieu of providing this downstream analysis, an applicant can simply provide Overbank Flood Protection Volume for the peak discharge from the 24-hour ten-year storm.

B. Stormwater management and development plans where applicable, shall be consistent with adopted and approved watershed management plans or flood management plans as approved by the Maryland Department of the Environment in accordance with the Flood Hazard Management Act of 1976.

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 [Note: This unofficial excerpt of the Cecil County Code is made available in this form for the convenience of interested parties and only the official Cecil County Code should be relied upon.]